Synthesis and antifungal properties of sulfanilamide derivatives of chitosan

Sulfanilamide derivatives of chitosan (2-(4-acetamido-2-sulfanimide)-chitosan (HSACS, LSACS), 2-(4-acetamido-2-sulfanimide)-6-sulfo-chitosan (HSACSS, LSACSS) and 2-(4-acetamido-2-sulfanimide)-6-carboxymethyl-chitosan (HSACMCS, LSACMCS)) were prepared using different molecular weights of chitosan (CS), carboxymethyl chitosan (CMCS) and chitosan sulfates (CSS) reacted with 4-acetamidobenzene sulfonyl chloride in dimethylsulfoxide solution. The structures of the derivatives were characterized by FT-IR spectroscopy and elemental analysis, which showed that the substitution degree of sulfanilamide group of HSACS, HSACSS, HSACMCS, LSACS, LSACSS and LSACMCS were 0.623, 0.492, 0.515, 0.576, 0.463 and 0.477, respectively. The solubility of the derivatives (pH < 7.5) was higher than that of chitosan (pH < 6.5). The antifungal activities of the derivatives against Aiternaria solani and Phomopsis asparagi were evaluated based on the method of Jasso et al. in the experiment. The results indicated that all the prepared sulfanilamide derivatives had a significant inhibiting effect on the investigated fungi in the polymer concentration range from 50 to 500 mu g mL(-1). The antifungal activities of the derivatives increased with increasing the molecular weight, concentration or the substitution degree. The sulfanilamide derivatives of CS, CMCS and CSS show stronger antifungal activities than CS, CMCS and CSS. (C) 2007 Elsevier Ltd. All rights reserved.

小麦高分子量谷蛋白亚基表达量与面团流变学特性的关系

应用SDS-PAGE技术依据HMW-GS组成型从来自全国10个省（区）、市的小麦品种（系）中筛选出20个,分为5组。准确提取各品种的高分子量谷蛋白,并将SDS-PAGE谱带用凝胶成像系统（Bio-imagingSystem）和Labworks5.0进行亚基定量分析,并进行了面团流变学特性测定,所得数据用SPSS14.0进行统计分析。结果表明,HMW-GS总表达量在各品种间的差异达到极显著水平,所有品种中各亚基的平均表达量10〉7〉5〉1〉8〉12〉2〉9;HMW-GS总表达量及HMW-GS占籽粒蛋白质含量的比例与面团形成时间、稳定时间和粉质评价值之间呈显著正相关;分组比较单个亚基对品质性状的影响表明,亚基1优于null,5＋10优于2＋12,7＋8和7＋9相当。研究发现不具有优质亚基组成、但HMW-GS表达量高的品种品质也较好,因此在小麦品质育种中,在注重HMW-GS组成筛选的同时,要注重保留HMW-GS表达量高的材料。

国产赖草属的分类修订

通过标本研究和野外考察,对中国赖草属(Leymus Hochst.)进行了分类修订.结果在中国共确认了3组、33种、7变种赖草属植物,其中多穗组包含4种,少穗组包含24种、7变种,单穗组包含5种,新报道的3个种和新修订的4个类群(即3个新组合和1个新名称)皆隶于少穗组.同时对赖草属的研究简史、属的形态特征和一些类群的地理分布也分别作了简要介绍.

高原鼠兔家群空间领域的季节性动态格局

为探讨高原鼠兔家群空间领域的季节特征,分别于2005年和2006年的5～8月,在青海省玛沁县,采用标志重捕法和最小多边形面积法对其家群巢区和核域进行了研究.结果表明,不同季节,高原鼠兔巢区和核域面积存在显著差异.5、6月份,成体巢区面积显著大于幼体,但二者核域面积却无显著差异;7月份,成体与第1胎幼体巢区及核域面积均显著大于第2胎.5、6月份雄性成体巢区显著大于7、8月份,6、7月份雌性成体巢区显著大于5月和8月份.巢区及核域面积均与家群个体数呈极显著性正相关关系,说明季节和家群结构均可对高原鼠兔空间领域产生重要作用。

退耕还林还草地鼠害治理——大林姬鼠种群年龄结构的研究

对采自青海省退耕还林还草地88只大林姬鼠Apodemus specivsus标本的体重和胴体重等7项生长指标进行了主成分分析，确定了各项指标时鼠体生长的代表性大小。结果表明：体重和胴体重是最具有代表性的生长指标，井根据体重将大林姬鼠划分为5个年龄组。为厦时掌握退耕还林还草地鼠类种群动态进而对其进行有效防治提供有力的证据。

红景天中红景天甙和酪醇的毛细管电泳法分析

利用毛细管电泳法分离测定两种红景天中红景天甙和酪醇的含量,所用毛细管规格为48.5 cm×50 μm, 二极管阵列紫外检测器 (DAD)检测波长221 nm, 最佳分离条件:电压21 kV, 分离温度25 ℃,背景电解质为含有30 mmol/L 十二烷基硫酸钠(SDS), 2.5+97.5(V/V)乙腈的14 mmol/L硼酸溶液,pH 10.7.红景天甙与酪醇分别在60.0～7.5 μg/mL 和 27.5～3.5 μg/mL质量浓度范围内与电泳峰面积呈现良好线性关系,检测下限分别为3.0和1.5 μg/mL .对标准品进行6次测定, 迁移时间的RSD为0.25%和0.39%, 峰面积的RSD为5.26%和3.52%.

二叶獐牙菜化学成分研究

从二叶獐牙菜(Swertia bifolia Batal.)的全草中分离得到了7个化合物,5种口山酮和2种甾醇类化合物.它们的结构经光谱方法分别鉴定为1-羟基-3,5-二甲氧基口山酮(Ⅰ)、1-羟基-3,7,8-三甲氧基口山酮(Ⅱ)、1,8-二羟基-3,5-二甲氧基口山酮(Ⅲ)、1,8-二羟基-3,7-二甲氧基口山酮(Ⅳ)、1,7-二羟基-3,8-二甲氧基口山酮(Ⅴ)、β-谷甾醇(Ⅵ)、胡萝卜苷(Ⅶ).

海北高寒草甸地区太阳总辐射、植被反射辐射的有关特征

祁连山海北高寒草甸地区，有较强的太阳总辐射及地表反射辐射。通过2000年观测结果表明，在植物生长期的4～10月，太阳总辐射和地表反辐射总量分别达4227.049MJ·m~(-2)和973.556MJ·m~(-2)。二者有明显的日变化规律，瞬时最高值出现于北京时间13～14h左右，日瞬时最大值分别可达1200W·m~(-2)和220W·m~(-2)以上。植物生长期间太阳总辐射变化受太阳高度角及其当地气候环境的影响，太阳高度角高或气候干燥时太阳总辐射值大，而地表反辅射依太阳总辐射的变化而变化，二者均在7月最高，5月次高。植物生长后期，气候湿润，太阳总辐射和地表反射辐射均较低。地表反射率不论在日间还是植物生长的季节间，均表现一“U”型变化过程，其中日间在中午前后最低，最低可达0.19季节变化以6～7月最低，约为0.21,当然受土壤潮湿程度及地表性质等影响，其它时间也可降到0.21。就整个植物生长期内来看，祁连山海北高寒草甸地区地表反射率平均约为0.23。

高寒牧区三种豆科牧草与燕麦混播的试验研究

在中国科学院海北高寒草甸生态系统开放实验站进行的燕麦与箭舌豌豆、红豆草、毛苕子3 种豆科牧草混播栽培的试验研究, 采用正交设计及极差分析方法对混播组合作择优评判。结果表明: 红豆草在年均温-1. 7 ℃, ≥5 ℃积温1 000 ℃, 海拔3 200 m 的高寒地区可与燕麦建立一年生混播割草地。其产量水平高于毛苕子与燕麦混播的草地而与箭舌豌豆与燕麦混播的草地相当。对豆科牧草种(A )、混作方式(B)、混播总密度(C) 和混播比例(D) 4 个因素进行择优组合可提高单位面积牧草产量。4 种试验因素对混播草地牧草产量的效应大小依次为C> A > D> B。本试验最优组合为5 号组合(A 2B2C3D1)。

高寒草甸植物地下生物量与气象条件的关系及周转值分析

分析高寒草甸植物地下生物量季节动态及年地下净生产量与气象条件之间的关系表明: ①高寒草甸植物地下生物量在牧草生长季的5～10月呈“N”型的变化规律, 10月最高, 6 月次高; 7月最低, 5月次低。地下生物量的这种季节性变化与土壤湿度的变化具有很好的滞后正相关。地下生物量的季节变化与同期气温、降水、地温等气象条件有一定的反相关变化规律, 且表明高寒草甸地下生物量对气象条件、特别是自然降水反应敏感; ②年地下净生产量各年间分布均不一致,年际间差异大, 受自然降水量影响较大。年内降水丰富, 地下净生产量提高明显, 生物量周转值也相应较高。平均来看, 高寒草甸地域植物地下年净生产量为1001. 5g/m2 (干重) , 周转值为0.369。

中国鹅观草属的分类研究

本文对中国鹅观草属Roegneria进行了分类修订,提出了一个新的分类系统。新系统包括19个新组合或新等级,并按照颖分组、芒分系的原则确认了中国该属植物4组、18系、79种、22变种,其中包括7新系、5新种和1新变种。此外,一些类群的省级分布新记录也在本文作了报道。

去甲肾上腺素刺激高原鼠兔CRF的分泌

We studied the effect of neuro transmitter no repin ephrine (N E) on immuno reactive cortico trop inreleasing factor (CRF) of median eminence (M E) in the native pika (Ochotona cu rz oniae). At one hour after intra cerebrovent ricular ( icv) adm inistrat ion of N E in doses of 3.75,7.5, 15 and 30 μg/100 g BW , the CRF level ofM E increased. And the plasma cortico sterone concent rat ion also increased. Two and six days after adrenalectomy (ADX) , N E concent ration in hypothalamus declined to 76.32% and 76.27% of those in intact pika, plasma cortico rsterone concent ration also decreased to 16.57 and 2.05% of the control. These results indicated that N E have a effect on activating HPA axis through activating hypothalamic CRF in Ochotona curzoniae.

Determination of free fatty acids in soil and bryophyte plants by precolumn derivatization via HPLC with fluorescence detection and tandem mass spectrometry (HPLC-MS/MS)

A sensitive method for the determination of 30 kinds of free fatty acids (FFAs, C-1-C-30) with 1-[2-(p-toluenesulfonate)-ethyl]-2-phenylimidazole-[4,5-f] 9,10-phenan- threne (TSPP) as labeling reagent and using high performance liquid chromatography with fluorescence detection and identification by online postcolumn mass spectrometry with atmospheric pressure chemical ionization (APCI) source in positive-ion mode (HPLC/MS/APCI) has been developed. TSPP could easily and quickly label FFAs in the presence of K2CO3 catalyst at 90 degrees C for 30 min in N,N-dimethylformamide (DMF) solvent, and maximal labeling yields close to 100% were observed with a 5-fold excess of molar reagent. Derivatives were stable enough to be efficiently analyzed by high performance liquid chromatography. TSPP was introduced into fatty acid molecules and effectively augmented MS ionization of fatty acid derivatives and led to regular MS and MS/MS information. The collision induced cleavage of protonated molecular ions formed specific fragment ions at m/z [MH](+)(molecular ion), m/z [M'+CH2CH2](+)(M' was molecular mass of the corresponding FFA) and m/z 295.0 (the, mass of protonated molecular core structure of TSPP). Fatty acid derivatives were separated on a reversed-phase Eclipse XDB-C-8 column (4.6 x 150 mm, 5 mu m, Agilent) with a good baseline resolution in combination with a gradient elution. Linear ranges of 30 FFAs are 2.441 x 10(-3) to 20 mu mol/L, detection limits are 3.24 similar to 36.97 fmol (injection volume 10 mu L, at a signal-to-noise ratio of 3, S/N 3:1). The mean interday precision ranged from 93.4 to 106.2% with the largest mean coefficients of variation (R.S.D.) < 7,5%. The mean intraday precision for all standards was < 6.4% of the expected concentration. Excellent linear responses were observed with correlation coefficients of > 0.9991. Good compositional data could be obtained from the analysis of extracted fatty acids from as little as 200 mg of bryophyte plant samples.Therefore, the facile TSPP derivatization coupled with HPLC/MS/APCI analysis allowed the development of a highly sensitive method for the quantitation of trace levels of short and long chain fatty acids from biological and natural environmental samples.

Pre-column derivatization of amines with 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl chloroformate followed by LC-fluorescence and LC-APCI-MS

A pre-column derivatization method for the sensitive determination of amines using the labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl chloroformate (BCIC-Cl) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives is carried out by high performance liquid chromatography/atmospheric pressure chemical ionization (LC-APCl-MS-MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent is replaced by 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl functional group, which results in a sensitive fluorescence derivatizing reagent BCIC-Cl. BCIC-Cl can easily and quickly label amines. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography and show an intense protonated molecular ion corresponding m/z [MH](+) under APCl in positive-ion mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 260 corresponding to the cleavage of CH2-OCO bond. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3 to 4-fold molar reagent excess. In addition, the detection responses for BCIC derivatives are compared with those obtained using CEOC and FMOC as derivatization reagents. The ratios of l(BCIC)/l(CEOC) and l(BCIC)/l(FMOC) are, respectively, 1.23-3.14 and 1.25-3.08 for fluorescent (FL) responses (here, l is relative fluorescence intensity). Separation of the derivatized amines had been optimized on reversed-phase Eclipse XDB-C-8 column. Detection limits are calculated from 1.0 pmol injection, at a signal-to-noise ratio of 3, are 10.6-37.8 fmol. The mean interday accuracy ranges from 94 to 105% for fluorescence detection with the largest mean %CV < 7.5. The mean interday precision for all standards is < 6.0% of the expected concentration. Excellent linear responses are observed with coefficients of > 0.9997.

Development of a sensitive fluorescent derivatization reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) and its application for determination of amino acids from seeds and bryophyte plants using high-performance liquid chromatography with fluorescence detection and identification with electrospray ionization mass spectrometry

A pre-column derivatization method for the sensitive determination of amino acids and peptides using the tagging reagent 1,2-benzo-3,4dihydrocarbazole-9-ethyl chloroformate (BCEOC) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives was carried out by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS/MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent was replaced by 1,2-benzo-3,4-dihydrocarbazole functional group, which resulted in a sensitive fluorescence derivatizing reagent BCEOC. BCEOC can easily and quickly label peptides and amino acids. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography. The derivatives showed an intense protonated molecular ion corresponding m/z (M + H)(+) under electrospray ionization (ESI) positive-ion mode with an exception being Tyr detected at negative mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 246.2 corresponding to the cleavage of C-O bond of BCEOC molecule. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3-4-fold molar reagent excess. Derivatives exhibit strong fluorescence and extracted detzvatization solution with n-hexane/ethyl acetate (10:1, v/v) allows for the direct injection with no significant interference from the major fluorescent reagent degradation by-products, such as 1,2-benzo-3,4-dihydrocarbazole-9-ethanol (BDC-OH) (a major by-product), mono- 1,2-benzo-3,4-dihydrocarbazole-9-ethyl carbonate (BCEOC-OH) and bis-(1,2-benzo-3,4-dihydrocarbazole-9-ethyl) carbonate (BCEOC)(2). In addition, the detection responses for BCEOC derivatives are compared to those obtained with previously synthesized 2-(9-carbazole)-ethyl chloroformate (CEOC) in our laboratory. The ratios AC(BCEOC)/AC(CEOC) = 2.05-6.51 for fluorescence responses are observed (here, AC is relative fluorescence response). Separation of the derivatized peptides and amino acids had been optimized on Hypersil BDS C-18 column. Detection limits were calculated from 1.0 pmol injection at a signal-to-noise ratio of 3, and were 6.3 (Lys)-177.6 (His) fmol. The mean interday accuracy ranged from 92 to 106% for fluorescence detection with mean %CV < 7.5. The mean interday precision for all standards was < 10% of the expected concentration. Excellent linear responses were observed with coefficients of > 0.9999. Good compositional data could be obtained from the analysis of derivatized protein hydrolysates containing as little as 50.5 ng of sample. Therefore, the facile BCEOC derivatization coupled with mass spectrometry allowed the development of a highly sensitive and specific method for the quantitative analysis of trace levels of amino acids and peptides from biological and natural environmental samples. (c) 2005 Elsevier B.V. All rights reserved.